Search found 563 matches

by 1024MAK
14 Sep 2019 18:49
Forum: OFF TOPIC
Topic: Substitute for Diode BAV199
Replies: 3
Views: 35

Re: Substitute for Diode BAV199

In what circuit and in which position is this for?

Mark
by 1024MAK
09 Sep 2019 22:24
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 21
Views: 488

Re: Another Home-Brew - Z180

A failure of a Z80 to accept a clock has been seen elsewhere (not that I can remember where mind) when driven with a normal 74LSxxx part.

And Sinclair used a transistor with a 180Ω to 330Ω pull-up resistor to buffer the ULA clock output to the NMOS Z80A in their ZX81 and ZX Spectrum models.

Mark
by 1024MAK
01 Sep 2019 13:10
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 21
Views: 488

Re: Another Home-Brew - Z180

Or use an expanded RC2014 backplane (see here for a selection).

Mark
by 1024MAK
01 Sep 2019 12:58
Forum: HARDWARE
Topic: Resurrecting an MTX500.
Replies: 226
Views: 10663

Re: Resurrecting an MTX500.

Well, at least you have got back to where you were :?

Mark
by 1024MAK
31 Aug 2019 13:56
Forum: MEMOFEST 2019
Topic: Memofest 2019 at Andys
Replies: 4
Views: 270

Re: Memofest 2019 at Andys

Well, I’ll be going ;)

Mark
by 1024MAK
23 Aug 2019 21:15
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 21
Views: 488

Re: Another Home-Brew - Z180

See also this site.

Mark
by 1024MAK
23 Aug 2019 20:55
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 21
Views: 488

Re: Another Home-Brew - Z180

I read the datasheet as: Z8S180 3.3V or 5V, 20MHz (or lower speed) operation. 5V, 33MHz operation. Z8L180 3.3V 20MHz (maximum) operation. I’m guessing that the S in the part number means high Speed, and the L in the part number means Low voltage operation, but have not found any Zilog documentation ...
by 1024MAK
17 Aug 2019 09:47
Forum: OFF TOPIC
Topic: Homebrew DIY SAM Coupe ?
Replies: 15
Views: 932

Re: Homebrew DIY SAM Coupe ?

Sounds interesting, I’ll have to visit your site more often.

By the way, you need to include the full link otherwise the forum thinks you are linking to another page on this site, so use http://www.samcoupe.com in the link tags ;-)

Mark
by 1024MAK
15 Jul 2019 16:59
Forum: OFF TOPIC
Topic: Alan Turing to appear on new £50 note
Replies: 0
Views: 165

Alan Turing to appear on new £50 note

Alan Turing to appear on new £50 note Quoting RetroTechie from World of Spectrum forums : Great when a giant of science & technology is honored this way: https://www.bankofengland.co.uk/news/2019/july/50-pound-banknote-character-announcement Just for laughs, they should wait until the note is 6-12 m...
by 1024MAK
14 Jul 2019 19:11
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 48
Views: 2207

Re: MTX 512 (debugging thread)

The left most voltage regulator is a 7812 and provides the +12V rail. The middle voltage regulator is a 7805 and with a TIP2955 helps provides the +5V rail. The right most device is not a voltage regulator, but a power transistor. This is a TIP2955. It boosts the current to increase the available cu...